Method or process of making twist-drills or the like.



J. B. MUORE.

METHOD 0R PROCESS OF MAKING TWIST DRILLS OR THE LIKE.

APPLICATION FILED APR. 13.1914.

Patented Dec. 29, 1914.

Original application filed December 1%,

n The Parent onrio.

aomr :B. moons, or nirrnonn, rnmisrtvnnm, nssienon 'ro nn'rnonn root coarreirr, or harness, PEHBZ'SYEWANIA, a conronerroit or rnrmsrnvnnta wearer.

' To all whom it may mam:

Be it known that l, JOHN B. Moonn, a

citizen of the United States, residing at Latrobe, in the county of F]estmoreland and State of Pennsylvania, have invented new and useful improvements in Methods or Processes of Making 'iWist-Drills and the like, of which the iollowinglis a specification.

lhis invention relates f'to an improved method or process .otrinaking twist drills and the like, this case being-re. division ofthe application filed by'- -meDec 18, 1913, Serial No. 807,525. I

Owing to the excessive cost of the high speed steels of, which twist drills, and the like, are usually constructed, attempts have beeninade from. time to time toconstruc't' such drills in two parts b forming the body or working portion of high grade material and securingfthe same to a shank of ordinary carbon steel. Such structures, however, are "open to the objection that they are weakest at the point ofunion between the body and the shank, and areeasily brokenw atthat point-under the strains encountered by the tool in operation.

One ofthe objects'olc' the present invention is to produce a two part drill, z. e,

' a drill formed with a body of high speed steel and a shank ofcarbon steel, which will conform'to' the general outline of the old style of drills constructed by milling, and which will have its greatest strength at the point of union between the body and the shank.

The invention will be hereinafter fully 'set forth and particularly pointed out in the is a view of the finished drill. Fig. i is-a v1ew of a finished (hill with a straight ,Referring to the drawi'ngs, 10 designates a blank of any 'suitable-high grade material Specification 01'' Letters Zatent.

7 METHOD 0R PRGUESS @li' MdmNG TWEST-DRILLS Patented 29, iltl ld.

1913,. Serial Ito; 805,525. Divided and this application filed il'pri! 13,1814. Serial No. atl/lel;

of which the-body of the drill is to be made, the same being provided with longitudinal grooves so as to be approximately T l-shaped in cross section as indicated at 11.. shank member 12 of lowergrade material is provided with a tang portion adapted to litv a drill socket, and it is also provided with a portion l2 providedwith recesses 13 so as to cause the same conform to the cross section of the blank 10. In practice the blank 10 and the shank-member 12 are placed in a suitable electrical welding apparatus, and'unite'd by a butt weld as indicated in Fig. 3, the pressure of bringing the parts together causing the metal to squeeze out at the joint to form what is termed the .59 flash as: indicated at 14.. This fiashf maybe removed by any suitable means, ii": desired, although l do not find it necessary to the success of my invention, to so remove it. After the parts are welded. together in the manner thus described, 1 splice the joint formed by the welding, by filling in the grooves 11 and recesses 13 with molten metal, preferably using the cry-acetylene blow. pipe for the nurpcse of welding the splicing material directly to the body and shank so as to become practically integral therewith, as indicated l5, l ig. suitable material may be used as a filling to'form a splice, and l do not desire to limit myself in this particular. Excellent results The have been obtained by using steeLphosphorbronze and the like. After the filling or splice has been applied to the parts the tool is read for the final finishin ste s and.

equally abplicahle to drills that are not twisted. it will be further understood that while have described the drill body as made of flat metal twisted after its union to the shanlr member, 1' do not desire to limit myself thereto, as it is obviousthat the drill body may be twisted before-the welding operationtakes place.

From what has been said it will be observed that by' means ofmy method-of uniting'the'parts I- am enabled to produce a-twee part dllll comprising abodyj of high speedsteel and ashank of carbon steel whichcconforms in general outline to theold 'style V drills-made by milling; It'will be further" notedthat the drill thus constructed hasno enlargements at thepoint of union betweenthe body and the-shank, andby reason of the splicing of the joint in "the manner described, the drill possesses greater strength at the jointthan' elsewhere so that it will-notbre'akat that point. Furthermore by unitdescribed, the body may be heated and twistingY-the body 1 and the shank inthe manner I mi h grade 'metal bodyto amend of a low grade shank, and splicing the joint thus; 0 a. v v

rmed with fluidmetal. r

*2. Ther mthdd of'f orimng; twist and a the like comprising the we'lding'of a high V grade'metal body? to a low gradeshank, r'emoving the'flas'h, and finally splicing the joint with fluid metal.

3. The method of forming twist drills and the like comprising welding a .high. grade I fmetal grooved body to a lowgrade metal shank having a recess,'and filling said recess and part of the'grooved portion of said body with fluid metal to form a splice.

metal body to one end of a low grade metal shank, splicing the joint thus formed with fluid metal, 'andfinally twisting said body 7 and finishing.

In testimony whereof I have-hereunto set .my hand in presence of-twosubscribing witnesses.

' JOHN vB, MOORE.

. 'witn'esse'si 1 p v 1 Jae. I. HUGHES,

WM; s Hobens 4:. The method of forming twist drills "comprising welding one end of ahigh grade 

